A Wide Angle on Chemical Sensing

Organization: MIT Lincoln Laboratory
Co-Developer(s): Eric R. Statz, Principal Investigator, Jonathan Ashcom, Alan DeCew, Brian Player, David Schue, Tina Shih, Alexander Wilson, John Zayhowski
Year: 2014

2014 R&D 100 Winner Detection and measurement of trace gases at low concentrations, in the presence of dynamically changing contaminants and at significant standoff distances, has important applications in both the civil and defense spaces. The detection and localization of gas releases such as methane from leaking natural gas pipelines or nitrogen oxides from failing electrical equipment requires high sensitivity to the target gas and insensitivity to other atmospheric contaminants, and, ideally, can be performed at long ranges. MIT Lincoln Laboratory’s Wide-Area Chemical Sensor (WACS) system uses a tuned, broadband laser coupled to a lossless, spectrally discriminating receiver to detect gases at sensitivities as good as typical local detectors, at ranges up to tens of kilometers, while compensating for atmospheric contaminants and instrumental drift.

WACS’s enabling technology, a single lossless optical resonant cavity (Fabry-Perot etalon), spectrally separates light that sees the gas of interest from light that doesn’t by tuning the cavity to coincide with the gas absorption. All light encountering the cavity transmits through it or reflects off of it; comparison of these two light intensities allows measurement of the gas-induced absorption, which varies over the bandwidth of the optical cavity’s spectral response for time-varying, but spectrally constant, losses caused by atmospheric scintillation and other atmospheric contaminants.

Technology Chemical sensor

DevelopersMIT Lincoln Laboratory

Development Team

 [[{"fid":"158136","view_mode":"default","fields":{"field_file_image_alt_text[und][0][value]":"","field_file_image_title_text[und][0][value]":""},"type":"media","link_text":null,"attributes":{"height":400,"width":308,"class":"media-element file-default"}}]]
MIT Lincoln Laboratory's Wide-Area Chemical Sensor (WACS) development team. Front row (l-r): Eric Statz, Jonathan Ashcom and David Schue. Middle row (l-r): Tina Shih, Brian Player and John Zayhowski. Back row (l-r): Alan DeCew and Alexander Wilson.

















The Wide-Area Chemical Sensor (WACS) Development Team from MIT Lincoln Laboratory Eric R. Statz, Principal DeveloperJonathan AshcomAlan DeCewBrian PlayerDavid SchueTina ShihAlexander WilsonJohn Zayhowski